Representatives of Trans-Canada -- the owner of the Keystone Pipeline -- met with North Dakota’s Public Service Commissioners to talk about a big oil spill in northern South Dakota, and the company’s response to it.

The pipeline leaked 210,000 gallons of oil near the South Dakota city of Amherst.

The Keystone Pipeline runs through North Dakota into South Dakota.

North Dakota Public Service Commissioner Julie Fedorchak said PSC members wanted to know why it happened, and to be updated on the clean-up efforts. Fedorchak said the company's quick response to the spill shows its response plan worked perfectly.

"The system was shut down within three minutes," Fedorchak said. "And importantly, the spill was detected."

Fedorchak said the spill showed up on its detection equipment, and the people overseeing system noticed it, and.

"They knew it was something off," Fedorchak said. "And the quick shutdown prevented what could have been a much more difficult spill."

But Fedorchak said there are still questions about why the spill happened.

"It's a new line," Fedorchak said. "New lines like this shouldn't be having those kinds of issues."

Fedorchak said it's important that the company and federal pipeline regulators do the tests needed on that pipeline, to try to figure out what caused it.

"That'll be a learning opportunity for the entire industry," Fedorchak said.

The company believes it may have been caused by an abrasion on the pipeline coating, that happened during construction.

"Perhaps there were some things in the ground that could have caused it," Fedorchak said. "Or it could have been a problem with the pipeline protection itself. They're looking at a number of things."